How to Make It
Mix the eggs into the milk in a small bowl and stir in the melted butter. Sift the flour and salt together, and put into a medium bowl. Add the wet ingredients and mix until well combined, I sometimes use an immersion blender to get it super smooth. It should be slightly thicker than heavy cream, but very fluid and pourable. Let sit at room temperature for 30-120 minutes before making crepes.
In a large nonstick skillet over medium high heat, cook the sausage, using a spatula to break the meat up into crumbles, and cooking until browned and cooked through. Remove the sausage to a bowl, leaving the fat in the skillet. Eyeball how much fat is left, you want about 3 tablespoons. If you don’t have that much, add a bit of butter to get to that 3 tablespoon mark.
Preheat oven to 300°F. Grease a large baking tray with olive oil.
Beat the egg with the olive oil until smooth. Mix with the ricotta until you get a soft blend, then add parsley, salt and pepper. Set aside.
Preheat the oven to 350°F. Layer 2-3 crepes to cover the bottom of a greased 9x13 casserole dish. Spread 1/2 of the ricotta mixture over the crepes. Layer 1/2 of the tomatoes over the cheese mixture, then pour 1/2 of the sausage gravy over the tomatoes. Repeat this layering. Add a last layer of crepes on top of the last layer of gravy. Cover the casserole with foil and bake for 30 minutes. At the 20 minute mark, make the eggs.
Beat the eggs in a medium bow with the grated butter until combined. Melt the last tablespoon of butter in a large nonstick skillet over medium high heat. Scramble the eggs to soft curds. You want these looser than you might think because they will continue to cook in the casserole. Set aside.
Remove the lasagna from the oven and discard foil. Turn on the broiler. Spread the eggs on top of the dish and then sprinkle the top with 2 cups shredded full-fat mozzarella and 1/2 cup grated Parmesan. Return the dish to the oven for 4-5 minutes until cheese is melted and slightly browned.